This is why Johnson, a participant in an innovative grower panel at the 2007 Beltwide Cotton Conferences in New Orleans, focuses on making sure selected high-cost inputs provide a good level of return on investment.

“The most important thing for us is to focus on soil fertility and pH. We became concerned about this several years ago when we started seeing that some of the top-producing cotton fields on our farm weren't making the good yields that we were expecting in good years. Also the crop didn't seem to have much ability to handle stress in dry years.”

Johnson hired a consultant to sample some of the fields in question on 2.5-acre grids. “In one field, we had an average pH of around 5.6, which is well below where we would like to see it. We had a good portion of the field in the 5.2 to 5.4 range.

“Our first goal was to bring the entire field into the 5.8 range and ultimately we are shooting for a minimum pH of 6.0. A prescription application map of the field in 2000 showed portions of the field called for over 2 tons of lime. An application like that is difficult to apply in one pass and even more difficult to pay for. So we implemented a program where we budgeted a certain amount each year toward fertility and pH, and took soil samples about every three years.”

In 2003, the field was re-sampled “and there was a dramatic improvement in pH after we had made two variable-rate lime applications. And the prescription map taken from those samples showed we had a very manageable application to bring the entire field up to 6.0.”

Yields improved

Crop yields have also improved with variable-rate applications of lime and fertilizer, “and we've avoided some poor yields that could have come during years that weren't that good for cotton in Tunica.”

In the fall, Johnson uses a Paratill subsoiler to break up any hardpan. “That's followed by a middle buster and a roller to freshen up our seedbed. One implement we've been pleased with is a combination bedder-roller which works well in certain soil conditions. It puts up a nice, wide, seedbed with a flat top that is easy to plant on. We also like the cost savings from being able to combine two operations in one trip through the field.

“In situations where we don't have existing seedbeds to follow, we use a GPS auto-steer system to put up our beds. We are on a 12-row, 38-inch spacing pattern. We feel like the guidance system does a much more uniform job and is much easier on the operator.”

In late February or early March, Johnson will make a burndown application of glyphosate “plus we'll have to add either 2,4-D or Clarity for glyphosate-resistant horseweed, which has become a very serious issue in our area.

“The next time we enter the field will be for planting. This is an area where I think we can shave some costs by decreasing our seeding rates from what we were doing 10 years ago. There may be some debate on this, but we feel like with seed populations of around 40,000 per acre in good soil and environmental conditions, we're safe, and it seems to be working for us.”

Most of Johnson's varieties are either Roundup Ready or Roundup Ready Flex cotton lines. “Our herbicide program is primarily glyphosate underneath the crop with a hooded sprayer or over-the-top with a ground rig or an airplane. We've had Flex cotton on our farm for two years, with about 15 percent planted to Flex varieties in 2006.

“We were really pleased with the results, especially in areas where we've had significant pigweed pressure in the past.”

Bt cotton

The farm plants mostly Bt cotton outside of the refuge areas. “After we get through our early-season pests and cutworms, we're mainly scouting for plant bugs.”

Harvest season begins around mid-September, “and is another area where new technology has made an impact. We take the GPS equipment out of our tractors and sprayers and install them on our cotton pickers.”

Yield monitors on the pickers indicate to Johnson where problem areas in the field are located. “We also quantify how much these problems areas cost us. If we have a low fertility area that has shown up in our soil samples, the maps can motivate us a little more into taking care of it.”

Another use for yield monitors is on-farm test plots. “We'll try two different practices and we can get a good comparison on the yield map.

“We've implemented all these practices to stay productive, and I think use of new technology is one key to that,” Johnson said. “I'm also excited about the things I see on the horizon, especially the coming new technologies in cotton for harvesting.”